Distributed Online Monitoring of Quasi-Static Voltage Collapse in Multi-Area Power Systems

This paper presents a novel performance index for distributed monitoring of quasi-static voltage collapse in multi-area interconnected power systems. Based on the sensitivity of the smallest singular value of the power flow Jacobian matrix with respect to the regional load vector, the performance index applies overlapping decomposition in order to monitor the entire interconnected system with minimal area-level information exchange. Theoretical justification and practical implementation of distributed voltage stability monitoring are presented. By comparing the value of the performance index with a numerically robust threshold at each administrative control area, each area will be able to monitor quasi-static voltage instability at the entire interconnection level. Numerical simulations in the IEEE 300-bus system illustrate the effectiveness of the proposed performance index and the threshold.